If a tool or codebase is unpleasant to work with, productivity will
drop.  The problem is not that programmers are lazy or undisciplined,
but that we all have a mental "gag reflex" and overcoming it takes
energy.  On a good day, the required energy is simply subtracted from
that which would otherwise be applied to productive work; on a bad day
it exceeds the energy available and absolutely nothing gets done.
Making programmers work on awful code is like requiring them to run an
obstacle course every hour.

		-- Jeff Darcy